Heterosexual sex is the primary mode of HIV transmission in Uganda, which is likely why prevalence increases dramatically from middle to late adolescence as young people become sexually active. Indeed, the percent of women with HIV jumps from 1.6% among 15- to 17-year-olds to 5.1% among 18- to 19-year-olds, and increases further to 7.1% among 20- to 22-year-olds. For males, rates also rise from 1.8% to 2.3% as they age from 15-17 years to 20-22 years of age. Clearly, curbing the HIV epidemic in Uganda requires culturally salient and theoretically-driven HIV prevention programming that is easily accessible to adolescents as they age through this period of risk. Given the epidemiology of the HIV epidemic in Uganda, intervention during late adolescence (i.e., 18-22 years of age) is key. We propose to develop the first-of-its-kind comprehensive HIV prevention program for Ugandan adolescents, timed to arm them with the skills necessary to reduce their HIV risk precisely as they move through a high-risk period. Being text messaging-based will ensure that the program is low-cost and easily scalable. By harnessing Facebook and other online resources, this proposal will be one of the first to develop and test an intervention nationally in Sub-Saharan Africa. Specifically, we aim to: Specific Aim 1: Design a 6-week text messaging-based HIV prevention and healthy sexuality program for adolescents 18-22 years old. Older adolescents will be recruited as focus group participants (n = 40) to explore acceptability of proposed program components (e.g., program length) and identify vernacular and voice that can be integrated into program messages. Once a draft of the messaging has been written, we will recruit a Content Advisory Council (CAC; n = 15) that will provide reactions to the content, scope, style, and tone of the messages. After integrating feedback, a second CAC (n = 15) will be conducted to confirm the suggested improvements have been translated effectively. Specific Aim 2: Pilot test the intervention for feasibility and acceptability among 18- to 22-year-old Ugandans (n = 200). Participants will be randomly assigned to the intervention or inactive control group. Our main outcome measures will focus on feasibility (e.g., recruitment and retention rates) and acceptability (e.g., Text Buddy, message content). Participants will be recruited online, mainly through Facebook. Specific Aim 3: Obtain preliminary data needed for a larger-scale controlled trial services study to examine program efficacy.